1. Field of the Invention
This invention relates to apparatus for distributing a stack of roof panels atop a building roof structure, either during initial construction or while existing roof panels are being replaced, and more particularly to a new and novel self-loading "low height" cart which will lift a relatively heavy, roof-mounted stack of panels to an elevated position relative to the underlying roof structure, transport the stack along a rail secured atop the roof to any selected one of a plurality of different positions on the roof, and then lower the stack at an adjusted position on the roof.
2. Description of the Prior Art and Objects of the Invention
Steel buildings are conventionally constructed with a "red iron" frame having a roof structure which includes an underlying matrice comprising a plurality of generally parallel, spaced-apart relatively heavy roof rafters and a plurality of relatively lightweight, transversely extending, panel support stringers or purlins. The rafters of a typical steel building may be 24 to 30 feet apart, whereas the transversely extending purlins, which are substantially lighter than the relatively heavy rafters, may typically be spaced at five foot intervals. Conventionally, the rafters are covered with steel roof panels which are initially delivered to the roof in a stacked bundle. Lifting cranes have sometimes been employed heretofore for supplying the stacked bundle to the roof structure and then distributing the individual panels about the roof area.
Steel roof panels are typically provided in banded bundles which the workers sometimes previously "rolled" over the roof purlins onto the portion of the roof panels which they had just laid. To accomplish this, the workers heretofore walked on the underlying purlins. This maneuver is relatively dangerous, difficult and time-consuming, and interferes with the laying of the roof panels.
A prior art roof panel distributing cart, sold under the trademark "Magic Roofer", has been provided heretofore but is relatively complicated and includes clamps and rollers which must be assembled on the roof. With the prior art "Magic Roofer" cart, the roof panels were loaded on the end of the roof, opposite the start end, and then moved the entire length of the roof.
Accordingly, it is an object of the present invention to provide new and novel apparatus for moving bundles of roof panels atop the roof panels which were just laid without damaging the previously laid roof panels.
It is another object of the present invention to provide new and novel apparatus for distributing roof panels atop a roof by the bundle via a portable cart and a portable track on which the cart rides.
It is another object of the present invention to provide new and novel bundle moving apparatus which will minimize the manpower required to distribute roof panels on a roof.
It is another object of the present invention to provide apparatus for distributing roof panels, by the bundle, on a roof, either while the building is being built or during a roof re-covering operation, which apparatus will raise the relatively heavy bundles a short distance relative to the roof frame and, then, by means of rollers provided thereon, transport the bundles atop a rail, which is mounted atop the roof structure.
The apparatus constructed according to the present invention contemplates a carriage including an inner, downwardly opening, inverted U-shaped, elongate channel member mounting rollers for rollingly engaging a roof-supported track member, a load-carrying platform mounted on the carriage for longitudinal and vertical movement relative thereto, including an outer, downwardly opening inverted U-shaped, elongate channel which mounts guide rollers that are received in guide slots for upwardly urging the platform to elevate the roof-supported stack of panels as the platform and the carriage are relatively longitudinally moved via a pivotally mounted handle.
Accordingly, it is another object of the present invention to provide new and novel cart apparatus of the type described, including cooperating slots on one of the carriage and the load-carrying platform and laterally extending roller pins mounted on the other of the carriage and the platform and received by the slots for guiding the relative vertical paths of travel of the platform and the underlying carriage as the platform and underlying carriage are relatively longitudinally moved.
The present invention contemplates an elongate handle pivotally mounted on one of the carriage and the load-carrying platform and a coupling member coupled between the handle and the other of the carriage and load-carrying platform to relatively longitudinally move the load-carrying platform and the carriage for upwardly camming the platform to lift the load relative to the underlying roof structure. Once the load has been lifted, the handle will substantially unassistedly remain in the load-lifting position, without the necessity of a lock.
The apparatus constructed according to the present invention further contemplates a bundle support frame which is mounted on the roof and includes a generally inverted U-shaped support member which overlies the track and underlies and supports the stack of roof panels a sufficient distance to permit the track-mounted cart to pass thereunder. The inverted U-shaped support will be elevated and carried by the cart as the stack is moved and, thus, the support platform will remain in a position underlying the stack, as the stack is lowered in the reset position. Accordingly, the user can move the stack along the length of the underlying rail and reset it in an adjusted position, without the necessity of having additional workers move the underlying stack support platform.
The present invention further contemplates the use of an upstanding bracket or stop, mounted on a "stop-end" of the roof-mounted track, having a portion thereof in the path of the cart such that, when the cart reaches the "stop end" of the track, the user can set the bundle and the underlying U-shaped bundle support on the roof and then continue bodily movement of the entire cart relative to the bundle and support. As the cart continues to be bodily moved relative to the bundle and support, it engages the upstanding track-supported bracket, whereby the underlying track will be carried thereby to the next longitudinally adjusted position in which the end opposite the "stop end" is drawn to a position underlying the stack. The user will then merely return the cart, in an opposite direction, on the repositioned track to a position underlying the inverted U-shaped stack support member and stack and will operate the cart handle to lift the platform relative to the carriage and again raise the stack so that it can be moved along the length of the repositioned underlying track. By repeating this operation, the relatively short rail is repositioned along the entire length of the roof to provide a continuous effective length which is much greater than its actual length.
Accordingly, it is an object of the present invention to provide new and novel cart-loading and moving apparatus of the type described, including an underlying track, which is substantially shorter than the length of the roof, and cooperating mechanism on the track and cart for repositioning the track to provide a continuous track the entire length of the roof.
Various low height trolleys have been provided heretofore for handling heavy articles such as that disclosed in U.S. Pat. No. 2,546,539 issued to M. H. Fehn on Mar. 27, 1951; U.S. Pat. No. 2,638,354 issued to H. J. Larson, et al on May 12, 1953; U.S. Pat. No. 2,981,350 issued to R. L. Zouck, et al on April 25, 1961; and U.S. Pat. No. 3,091,477 issued to G. B. Johnstone on May 28, 1963. None of these patentees disclose applicant's construction and do not even appreciate the problems which applicant has solved.
Other objects and advantages of the present invention will become apparent to those of ordinary skill in the art as the description thereof proceeds.